Having, er, slept on this thought, if you were unable to sleep because you were earthed for a change, then clearly your body is having some kind of reaction to being earthed. If this is true, and earthing is ultimately benign, then I'm left wondering whether the earthing you're getting during the day is of adequate quality. It'd be really interesting to see what happened if you could ride through your body's reaction to being earthed, as I'm thinking that you might come out the other side with a happier physiology. Rather than go through sleepless nights I'm wondering if you could make use of the sheet and other good options to make sure you're earthed as well as possible for as long as possible whenever you're not trying to sleep, and see if anything changes over the course of a few weeks (including whether you then find that you can sleep earthed).
Of course, if the sleeplessness was due to the physical presence of the earthing sheet, or skin irritation, or whatever, then the above may not apply.
Of course, if the sleeplessness was due to the physical presence of the earthing sheet, or skin irritation, or whatever, then the above may not apply.